Ways to get an user M code return value

Hi!

I have read some statements that there is currently no direct way to get a return value of my user defined M function back to the G code. My questions:

1.) Is there a way to set parameters (like #4999) directly in the M code?

2.) One working way is to set HAL pins/parameters via "halcmd" and then read them out in the G code.
Is there a (very simple) hal module which only offers some parameters to be used as a "clipboard" between M code and G code?
As I understood HAL there is no function needed for updating something because there are no inputs and outputs needed, just parameters. Before I write such a module - has it already been written?

Best regards,
Chris

I would use a python remap.
Create a file 'remap.py':
mark the file as executable and place it in a folder 'python' in your machine config

then add this to the [RS274NGC] section in your ini file:
In your gcode you should then be able to do something like:

which should move the x axis to 4



 

Ahh, perfect

Thank you very much!

I would be interested to know experiences here in WHEN the remapped m word is executed.  I did this (M259) to run some halcmd lines to set pins in hal and found that this was being executed as soon as the programe was parsed and then again when it was run.  But NOT when the line was encountered in the correct order in the program.  I could solve for preventing the parsing issue but could not find a way to get things to only happen at the correct point in the program run.

The only way I could solve this was to use the M100-M199 range of pre configured user available words.  These behave correctly in that sense. i.e. trigger only when encountered in the program execution.   I can't remember if they also prevent parsing execution, I already had the code to prevent that baked in.

So ... interested in your findings.

Cheers - J.

NB: using 2.9 debian install of linuxcnc.